arXiv subjects

S. Lotz

Publications and source records attributed to S. Lotz.

3 recordsLinked to original sources

arXiv2022

Heliophysics Discovery Tools for the 21st Century: Data Science and Machine Learning Structures and Recommendations for 2020-2050

Three main points: 1. Data Science (DS) will be increasingly important to heliophysics; 2. Methods of heliophysics science discovery will continually evolve, requiring the use of learning technologies [e.g., machine learning (ML)] that are applied rigorously and that are capable of supporting discovery; and 3. To grow with the pace of data, technology, and workforce changes, heliophysics requires a new approach to the representation of knowledge.

astro-ph.IM↗

arXiv2022

The radial variation of the solar wind turbulence spectra near the kinetic break scale from Parker Solar Probe measurements

In this study we examine the radial dependence of the inertial and dissipation range indices, as well as the spectral break separating the inertial and dissipation range in power density spectra of interplanetary magnetic field fluctuations using {\it Parker Solar Probe} data from the fifth solar encounter between $\sim$0.1 and $\sim$0.7 au. The derived break wavenumber compares reasonably well with previous estimates at larger radial distances and is consistent with gyro-resonant damping of Alfv\'enic fluctuations by thermal protons. We find that the inertial scale power law index varies between approximately -1.65 and -1.45. This is consistent with either the Kolmogorov (-5/3) or Iroshnikov-Kraichnan (-3/2) values, has a very weak radial dependence with a possible hint that the spectrum becomes steeper closer to the Sun. The dissipation range power law index, however, has a clear dependence on radial distance (and turbulence age), decreasing from -3 near 0.7 au (4 days) to -4 [$\pm$0.3] at 0.1 au (0.75 days) closer to the Sun.

astro-ph.SR↗

arXiv2021

The updated SANAE neutron monitor

Neutron monitors have been the premier ground-based instruments for monitoring the near-Earth cosmic ray flux for more than 70 years. It is essential to continue with such measurements in order to extend this unique long-term time series. Moreover, with the recent interest of the aviation industry to space weather effects, and especially the radiation risk posed by solar energetic particles and galactic cosmic rays, it is vital to extend the current neutron monitor network in order to provide near-real-time measurements to the space weather community. In this paper we discuss a new electronics system that was retrofitted to the SANAE neutron monitor in Antarctica. We present initial results from this system, featuring very high temporal resolution and discuss the techniques applied to the data analysis. Based on these successful upgrades, we are confident that this system can be used to rejuvenate the aligning neutron monitor network, and even possibly to revive some of the decommissioned instruments.

physics.space-ph↗